Clinical experience in seventy-seven patients with the automatic implantable cardioverter defibrillator

Abstract

Seventy-seven patients with drug-refractory sustained ventricular tachycardia (VT) (28 patients) or ventricular fibrillation (VF) (49 patients) underwent implantation of an automatic cardioverter defibrillator (AICD). The 67 men and 10 women, with a mean age of 60 ± 12 years (range 18 to 79), had coronary artery disease (60 patients), idiopathic cardiomyopathy (eight patients), mitral valve prolapse (four patients), hypertensive heart disease (one patient), Ebstein's anomaly (one patient), long QT syndrome (one patient), and primary electrical disease (two patients). The mean left ventricular ejection fraction was 35 ± 16% (range 10% to 75%). Sustained VT VF was induced in 64 patients (83%) at baseline electrophysiologic testing. A mean of 4.1 ± 1.3 antiarrhythmic drugs failed to control the arrhythmia. Associated surgery at AICD implantation included coronary artery bypass in 19 patients, coronary bypass with aneurysmectomy in six patients, and aneurysmectomy alone in one patient. Five patients had only prophylactic patches implanted during aneurysmectomy or coronary bypass and the AICD device was subsequently implanted under local anesthesia to prevent arrhythmia recurrence or to control persistently inducible VT. Operative mortality was 2.6% with two deaths from intractable VF. Fifty-two patients (69%) continued receiving antiarrhythmic drugs to suppress spontaneous VT. During a mean follow-up of 15 ± 13 months (range 1 to 63), six patients died: two suddenly due to probable pulse generator failure (> 2 years old), one of acute myocardial infarction, two of heart failure, and one of respiratory failure. By life table analysis, the 1-, 2- and 3-year overall cardiac survival was 95%, 95%, and 87%, respectively, and the fatal arrhythmia survival was 100%, 100%, and 92%, respectively. Late complications occurred in 10 patients and included two pocket infections, two postpericardiotomy syndromes, five premature battery depletions, and one accidental device deactivation. Twenty-six patients (35%) have received a total of 253 appropriate shocks for VT VF recurrences. Another 15 patients (20%) have had a total of 282 shocks deemed inappropriate. Thus the AICD is effective in the prevention of sudden death in patients in whom antiarrhythmic drugs or surgery have failed, with an acceptable operative risk and long-term complication rate.